1. Field of the Invention
The present invention relates to regulators for underwater breathing apparatus, in particular to regulators having a tube which bypasses the chamber of the air-flow regulating device.
2. Description of the Related Art
Regulators of this type are known in the art and consist, as described for example in U.S. Pat. No. 4,002,166, of a regulator comprising a box-like body containing an air-flow regulating device which is connected to an air inlet hose by means of a suitable valve controlled by the said regulating device and in which, downstream of the valve, a tube draws the air from the inlet hose and conveys it directly to a mouthpiece tube, thereby bypassing the chamber of the flow regulating device.
This type of bypass system was designed with the aim of making regulator operation easier. This is achieved because, by bypassing the chamber of the regulating device, a pressure drop is created in a known manner inside the chamber and this reduces the effort the diver needs to exert in order to inhale since the diaphragm in the regulating device is subjected to a pressure difference that allows it, via a lever, to act on the air inlet valve such that it opens the inlet hose.
Regulators of the type described above with reference to U.S. Pat. No. 4,002,166 nevertheless have certain disadvantages: the bypass tube through which the air is conveyed from the inlet hose to the mouthpiece is actually outside the box-like body of the regulator, which means that the mouthpiece tube and the air inlet hose need to be fitted with suitable connecting and sealing means in order to be coupled to the bypass tube, all of which does nothing for the structural compactness of the regulator.